docs: def collect_results(working_folder):
      """
      Collect results in a working_folder.
  
      The output is nested dict[rec_name][sorter_name] of SortingExtrator.
  
      """
      results = {} 
      working_folder = Path(working_folder)
      output_folders = working_folder/'output_folders'
  
      for rec_name in os.listdir(output_folders):
          if not os.path.isdir(output_folders / rec_name):
              continue
          # print(rec_name)
          results[rec_name] = {}
          for sorter_name in os.listdir(output_folders / rec_name):
              # print('  ', sorter_name)
              output_folder = output_folders / rec_name / sorter_name
              #~ print(output_folder)
              if not os.path.isdir(output_folder):
                  continue
              SorterClass = sorter_dict[sorter_name]
              results[rec_name][sorter_name] = SorterClass.get_result_from_folder(output_folder)
  
      return results